I started this awhile back and am hoping to complete by the deadline. I chose the mini castle because it was only 10 sheets. Zio's full size castle is 42 sheets. I have finished the 4 towers and the entrance portal.
large tower:
small tower:
entrance tower:
there are two entrance towers, one as shown one opposite
entrance portal:
Thats all I have done so far, I will try to get a lot done this weekend.

I finished most of the components for the mini castle this weekend,
well/fountain for the middle of the courtyard:
main building/house:
castle walls:
next will be gluing some of the components together and finishing the last parts, like walkways and the drawbridge.

Vermin King - to answer your questions, so far there haven't been any problems with the build. The notched tops of towers and walls were a little tricky because of all the small tabs, but if I can do them they can't be too difficult.

more progress on Zios mini castle,
assembled the two front towers, entrance portal and gate:
house, two rear towers, back wall, walkway and chimney:
front two walls and walkways:
next will be assembling all the sub-components and gluing to base.

I finished Zio's mini castle. There are some roofs that were part of the pattern, and I did build them but wasn't happy with them, so I decided not to use them. They were roofs over all four towers and all walkways. One of them had a design error that I needed to fix, but could never get it to fit right. Also, the roofs covered all the hard work on the tops of the towers and walls. So here are pictures of the finished mini castle,
Entry portal/drawbridge and the outsides of the walls: